Spring support



A. J. LOEPSINGER Sept. 6, 1949.

SPRING SUPPORT 4 Sheets-Sheet 2 Filed April 30, 1947 MW W 2? Sept. 6,1949. A. J'. LOEPSINGER simmc surron'r Filed April 50, 194'} 4Sheets-Sheet 3 Q grwwniov Med 72222 ea I 6mm,

Patented sept. 6, 194 9 UNITED STATES PATENT OFFICE Albert J.Loepsinger, Providence, R. 1., assignmto Grinnell Corporation,Providence, R. L, a corporation of Delaware Application April 30, 1947,Serial No. 744,852

11 Claims.

This invention relates to improvements in spring supports. Moreespecially it has to do with a spring support which within the limits ofits range permits a known load to move without being subjected to anysubstantial change in the lifting effect afforded by the support.-

The present support is generally of the same type and for the samepurpose as that disclosed in my Letters Patent No. 2,391,467, grantedDecember 25, 1945, but whereas in that patented support the primarylifting effect was supplied by direct acting main spring means and thevariations in that effect were compensated for by a component of theforce of auxiliary spring means. here both the supporting eflect and thecompensating eifect of the spring means act through a lever system inaccordance with the principle of moments.

Illustrative of a known load with which the improved support is usableis a piping system for conducting a fluid subject to wide variations intemperature. When the temperature rises the pipes in the system elongateand their elongation may reach several inches. This change in length ofthe vertically disposed portions of the piping system causes thehorizontal portions to move upward or downward as well. The upper limitof the displacement is commonly called the hot position and the lowerlimit the cold" position of the system. These positions may of course bereversed if the piping moves downward as its temperature increases.

v space of vertical extent, can be readily adjusted,

Except for relatively inconsequential changes the weight of the pipingsystem remains substantially constant. It is therefore important thatthe lifting efiect of the supporting means likewise remain substantiallyconstant regardless of the movement of the piping because if the load isnot properly supported at all times its movement may impose unsafestresses and reactive forces upon the piping itself or the fittings 0rapparatus to which it is connected, or upon both.

Therefore, the principal object of this invention, like that of myaforesaid Letters Patent No. 239L467, is to provide a spring supportcapable of exerting a substantially constant lifting effect on a loadthroughout its anticipated range of movement and to do this by combiningwith main spring means, whose supporting efiect necessarily changes assuch means are elongated or contracted in accordance with the loadmovements, auxiliary spring means which compensates for the variation inthe supporting effect of the main spring means. It is also among theobjects of the invention to provide apparatus and which follows the lawof moments in its operation.

The best modes in which it has been contemplated applying the principlesof these improvements are shown in the accompanying drawings but theseare to be deemed merely illustrative because it is intended that thepatent shall cover by suitable expression in the appended claimswhatever features of patentable novelty exist in the inventiondisclosed.

In the drawings:'

Fig. 1 is a top plan view of a spring support embodying my improvementsand showing the positions of the parts when the load is preferably atthe mid-point of its range of travel;

Fig. 2 is a side elevation of the same;

Figs. 3, 4 and 5 are elevations of certain of the elements to showvariations in some of the moments involved;

Fig. 6 is a plan in section taken as on line 8-8 of Fig. 2;

Fig. '7 is an elevation looking from the left in Fig. 2, the pipingbeing omitted;

Fig. 8 is another elevation looking from the right in Fig. 2, again withthe piping omitted;

Fig. 9 is a, side elevation showing the relative positions of parts ofthe support when the load has moved upward from its preferredmid-position;

Fig. 10 is another side elevation showing the relative positions ofparts when the load has moved downward from its preferred mid-position;

Fig. 11 is another elevation, s milar to Fig. 2, but showing a modifiedarrangement of the lever and the main spring means;

Fig. 12 is a left end elevation of the support shown in Fig. 11; and

Fig. 13 is a right end elevation of the same.

In the embodiment of the invention shown in the drawings, the mainspring means is a pair of tension springs II), III and the auxiliaryspring means is a compression spring l2. These spring elements and arotatable element H are mounted on a rigid frame I6 which can be securedto some fixed structural member (not shown) such as an I-beam or thelike.

The frame [6 comprises a pair of side plates Ilia and l6b held inparallel spaced relation by horizontal top plates I60 and I'Bd, whichmay be integral with or secured to the side plates along avertical-plate Hie interposed between the side plates close by one endof the frame. Near this same end of the frame a U-shaped yoke piece Ithas its legs secured to the side plates, preferably by welding, and tothe cross bar of this yoke is attached a tie rod 20 which in turn may beconnected to some overhead structural member. If desired, a reinforcingplate l8a. (see Fig. 7) may be inserted under the cross bar of the yoke.

An axle 22 extends through the side plates and is clamped thereto bynuts 24 threaded onto the projecting ends. This axle is positionedbetween the vertical spacer plate lie and the U- shaped yoke piece l8and on it is mounted the rotatable element, here shown as a simple bellcrank lever ll whose arms Ila and Nb, as seen in Figs. 1 to 10inclusive, are disposed at right angles to one another. Other forms oflever and indeed several levers could be used instead of the simple bellcrank. provided only that whatever lever system is employedthe principleor moments herein disclosed should be applied to the lever or system oflevers incorporated in the support. As here shown the upper or what maybe called the horizontal arm Ha extends toward the opposite end of theframe and is bifurcated (see Fig. 6) to permit the eye 26a of a hangerrod 28 to be positioned between the separated parts Ila and Ida" of thearm Na about an axle pin 28 extending across the separated parts andheld in place by cotter pins inserted. through holes of the pin outsidethe arm parts. The load, here represented by a pipe 30 secured to thelower hanger rod 26 by any suitable means such as a pipe clamp 3|, hangsvertically downward from the horizontal arm a of the bell crank.

The main spring means preferably consists of the two main tensionsprings Ill, l0 which act upon the depending arm Nb of the bell crank.This arm carries an axle 32 on each end of which is an eye bolt 34.Suitable washers are provided on both sides of each eye bolt and a pairof nuts 38 are threaded on each end of the axle to provide for properadiustment and for locking. On each eye bolt 34 is threaded the usualend plug 35 for engaging a spring, the plug having external helicalgrooves along which several turns of the springs are wound and having acentral threaded bore through which the shank 34a of the eye bolt isscrewed. This same arrangement is provided at the opposite end of eachmain spring (the corresponding parts having the same referencenumerals), where the main springs are pivotally attached to another axle42 carried in depending portions lfif of the frame side plates. Thisaxle 42. as shown in Figs. 1 to 10, is welded to the side plates and hasreduced portions for the eye bolts 34 and threaded end sections toreceive the adjusting and locking nuts 38.

arms so and s are equal. While this is the preferred relation of thesearms they could be of diilerent lengths if desired and this would makeno difference in the principle of operation but would only change thespring force proportionally to the diflerence between the lengths of themoment arms. With the moment arms 10 and 8 equal, the main springs arechosen or adjusted so that when the load is at a position correspondingto the horizontal position of the bell crank arm Ma the spring force 8equals the weight W of the load. Expressed as an equation WXw=SXs.

If now the load moves upward so that the bell crank assumes the positionshown in Fig. 4, (which might be deemed the hot" position 0! a pipingsystem), the load moment changes because, although the weight W remainsthe same. the new moment arm 10' is less than was the moment arm 10. Thenew moment arm s, of the main springs is also less than was the momentarm 8, but is substantially the same as the moment arm w. The springforce S exerted by the springs is now less than was the force S becausethe main springs have contracted. The change in spring force is theproduct of the spring constant times the reduction in length of thesprings. Accordingly, the new moments can be expressed as W w' S' s' andsince, as noted above, w and s' are substantially equal it follows thatthe spring force S is now less than the load W.

Conversely, if the load moves downward to bring the bell crank to theposition shown in Fig. 5 (which could be the cold position of a pipingsystem), the load W remains unchanged but its moment arm w" is less thanwas the moment arm 20. The moment arm 8" is substantially equal to themoment arm w" but less than was the moment arm s. The spring force S" isnow greater than was the spring force 8 The parts thus far described areshown in Figs. 1 and 2 when the upper arm Ha of the bell crank ishorizontal. The same position 01' the bell crank is reproduced in Fig.3. The load hangs vertically from the axle pin 28 and therefore themoment exerted on the bell crank by the load is the weight W oi the loadtimes its moment arm, the latter being the perpendicular distance tofrom the axis of axle 22 to the line of force 01 the load. The momentexerted on the bell crank by the main spring means is the force S of thetwo main springs times the moment arm of this spring force. This momentarm is the perpendicular distance s from the axis of axle 22 to the lineof force of the main springs.

because the main springs have been elongated. Accordingly. the newmoments can be expressed as WXw" S" s" and since w" equals s", thespring force S" is now greater than the load W. And here again thechange in the spring force is the product of the spring constant timesthe change in the length of the springs.

For purposes of illustration, the upward position of the load shown inFig. 4 is as far above the position shown in Fig. 3 as the positionshown in Fig. 5 is below the position shown in Fig. 3. Accordingly, thespring moment at the position shown in Fig. 4 is as much less than theload moment at that position as the spring I springs is difierent fromthe load being supported, and that the change in supporting eflectvaries solely in accordance with the movement of the load and the changein the force of the main springs. In other words, the moment exerted onthe bell crank by the main spring means increases or decreases as themain spring force increases or decreases, respectively. This variationin the supporting effect supplied by the main springs is not desirablebecause it is precisely the same as though the load were hanging from a.spring in tension or resting on a spring in compression with nointervening bell crank or other leverage mechanism interposed between Asshown in the drawings the two moment them. As the main springs arecontracted the supporting eflect decreases and as these springs areelongated the supporting eflect increases. In one case undesiredstresses are imposed on the remainder of the piping system by theunsupported portion of the weight of the load and in the other caseother such stresses are imposed by the excess supporting effect of themain spring means. Both of these dangerous results are avoided by thecompensating feature of the improved support.

This compensating feature is provided by having an auxiliary sprininterposed and so disposed between the frame and the bell crank that itwill exert a turning moment on the bell crank except when the mainspring moment, alone counterbalances the load moment.

Beyond the load axle pin 28, in direction away from the main axle 22, asecond axle pin 38 extends between the bifurcated parts Ma and I 4a ofthe upper arm of the bell crank. (See Fig. 6.) To this second pin isconnected an extended rod 40 which has secured to it a plate 43 havingon its surface remote from the eye of the rod a ring 43a constituting aflange for retaining one end of the auxiliary spring I! on the platesurface. The other end of this spring is retained by a similar flangering 44a on the surface of a second plate 44 threaded on a rod 46 andbacked up by a locking nut 45. The rod 46 extends to near the end of theframe side plates 16a and l6b where its hub 46a bears on an axle 48extending between the side plates and being secured thereto by nuts 50onits projecting ends. Suitable spacer sleeves 52 maintain the hub 46aat the middle of the axle pin 48 and thus keep the rod 46 in alignmentwith the rod 40 pivoted on the bell crank. Indeed, the rod 46 has a bore46b to receive the rod 40 as shown in Fig. 6. With the rods 40 and 48 indirect alignment with the upper arm |4a of the bell crank, as seen inFig. 2, it is evident that the auxiliary spring I2 has no efiectwhatever on the lifting effect afforded by the support because the lineof force of the auxiliary spring extends through the axis of the axle22, which axis may also be called the pivot of the rotatable element,and hence its moment arm is zero.

The compensating action of the auxiliary spring can best be described byreference to Figs. 9 and 10. In Fig. 9, the bell crank I4 is in the sameposition as is shown in Fig. 4 and, as previously described, the loadmoment is not counterbalanced by the main spring moment because with themain springs contracted the main spring moment is less than the loadmoment. However, the clockwise swing of the bell crank has caused therods 40 and 46, associated with the auxiliary spring I2, to assume aposition where nowthe auxiliary spring exerts a turning moment on thebell crank. The moment arm a of the auxiliary spring force A is theperpendicular distance from the axis of the axle 22 to the axis line ofthe rods 40 and 45, which is the direction of the force A exerted by theauxiliary spring. Since this moment arm can readily be determined, itonly remains to choose an auxiliary spring of the proper force and thenadjust the plate 44 by screwing it along the rod 46 until the auxiliaryspring exerts a moment on the bell crank equal to the difference betweenthe load moment and the main spring moment. By adding this auxiliaryspring moment to the main spring moment, since both moments are beinexerted clockwise on the bell crank, the two together willcounterbalance the load moment which is always acting counterclockwiseon the bell crank. Thus the net lifting effect or the support will bethe same when the bell crank is in the position shown in Figs. 4 and 9as it was when the bell crank was in the position shown in Figs.

. 2 and 3 and hence there will be no material change in supportingefl'ect on the piping system despite its upward movement. Expressed inthe form of an equation, W w=SXs'+A a'.

A like counterbalance occurs if the load moves downward so that the bellcrank assumes the position shown in Fig. 10, which is the same positionas shown in Fig. 5. In this instance the lifting effect of the mainsprings has increased due to the elongation of these springs. But nowthe swing of the bell crank has caused the auxiliary spring 12 and therods and 46 to move to a position where the auxiliary spring exerts amoment in the counterclockwise direction. This moment is the product ofthe moment arm a" times the force A" of the auxiliary spring.

If, as shown for purposes of illustration, the

downward movement of the load in Fig. 10 is the same as the upwardmovement indicated in Fig. 9, then the moment of the auxiliary spring isthe same in both positions except that in the upper position it isacting in a. clockwise direction whereas in the lower position it isacting counterclockwise. Accordingly, since the main spring moment atthe lower position of Figs. 5 and 10 is as much greater than the loadmoment as it was less than the load moment at the upper position ofFigs. 4 and 9, it follows that the net spring moment is the same at boththe upper and lower positions and is equal to the spring moment at thepositions of Figs. 2 and 3. Expressed as an equation for the lowerposition, WXw"=S" s"-A" a". Thus again the system is in balance and thelifting effect on the piping is the same as when the load was supportedsolely by the lifting efi'ect exerted by the main springs alone.

By suitable selection of springs, both main and auxiliary, together withthe adjustments provided for all the springs, the support will afford asubstantially constant lifting effect on the load throughout itsanticipated range of movement. When the direction of the line of forceof the auxiliary spring passes through the axis of the main axle 22, asshown in Fig. 2, the auxiliary spring exerts no turning moment whateverand the load moment is then counterbalanced solely by the moment of themain springs. As the bell crank' swings in either direction, there isestablished a moment arm for the force of the auxiliary spring, small atfirst as the bell crank begins to swing and the force of the auxiliaryspring is greatest. Then as this spring force lessens due to theelongation of the auxiliary spring its moment arm becomes appreciablygreater and at a greater rate than the force of the auxiliary springdiminishes. As a result the moment of the auxiliary spring keeps pacewith the change in the moment of the main springs and in suflicientlyclose step therewith to provide substantially a constant supportingeffect on the load throughout its anticipated movement.

It isto be noted that although the preferred use of the improved supportcontemplates that I the load shall be at the mid-position of its travelwhen the arm l4a 0f the bell crank is horizontal, this is not arequirement. The position of the load with the arm l4a horizontal may beeither at the top of its anticipated displacement or at the bottomthereof, and; indeed, the limits of travel of the load may be with thearm Ila either wholly above or below its horizontal position. For anyone size of support such an arrangement would necessarily reduce therange of travel of the load and so it is preferred to have the load atits mid-position or its displacement when the arm Ila of the bell crankis horizontal as shown in Fig. 2.

The modification disclosed in Figs. 11 to 13 perform in precisely thesame manner as already described. In this arrangement the main springsare mounted on the same axle a on which the rod 46 of the auxiliaryspring is pivoted. In this arrangement the bell crank arms Na and Nb areso disposed that when the upper arm Ha is horizontal, the axial line ofthe lower arm Mb (being the axial line between the axis of the main axle22 and the axis oi the spring axle 32) is perpendicular to thelongitudinal axes of the main springs. If the: moment arms of the loadand the main spring force are equal when in the positions justdescribed, then they will vary in the same amount upon movement of theload either upward or downward and thus the change in supporting efiectprovided by the main springs will vary as these springs are elongated orcontracted. As before, the lifting efi'ect of the main springs on theload varies Just as it would if there were no bell crank and the loadwere hanging directly from the main springs. But this variation iscompensated for by the action of the auxiliary spring because its momentwill be either added to or subtracted from that of the main springs asthe load moves upward or downward respectively.

Although I have shown in the drawings main spring means employingtension springs and auxiliary spring means using compression springs,this particular arrangement is only illustrative because the springmeans as a whole may comprise various combinations of compression and/ortension springs. Regardless of the kind of springs used the essence ofmy improvements is to so apply the force of these springs that themoment arm of the weight of the load and the moment arm of the force ofthe main spring means remain substantially equal, or in substantiallythe same proportional relation or ratio to each other as the load isdisplaced and the moment exerted by the rrain spring varies from theload moment in accordance with the change in the main spring force. Andthe moment exerted by the auxiliary spring means varies as the load isdisplaced to compensate for the aforesaid variation in the moment of themain spring means. This the net I supporting effect exerted by bothspring means on the load remains substantially constant throughout therange of travel of the load.

I claim:

1. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a fixed element; a rotatableelement to which the load is connected and on which the load exerts aturning moment in one direction; main spring means connected to saidfixed element and to said rotatable element and exerting a turningmoment on the latter element in direction opposite to that exerted bythe load, the said main spring means and the said load operating on thesaid rotatable element in such manner that throughout the said range ofdisplacement the moment arms of the said turnin forces havesubstantially the same proportional relation and the moment exerted bysaid main spring means increases or decreases as the main spring forceincreases or decreases, respectively; and auxiliary spring meansinterposed between said fixed element and said rotatable element andeflective uponmovement or the load to exert a turning moment on therotatable element which compensates for the variation in the turningmoment exerted by the main spring means; the moments of said lead andsaid main spring means being in balance when the line of force of saidauxiliary spring means passes through the pivot 01 the said rotatableelement.

2. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a fixed elment; a rotatableelement to which the load is connected and on which the load exerts aturning moment in one direction; main spring means connected to saidfixed element and to said rotatable element and exerting a turningmoment on the latter element in direction opposite to that exerted b theload, the said main spring means and the said load operating on the saidrotatable element in such manner that throughout the said range ofdisplacement the moment arms of the weight oi. the load and of the forceexerted by the main spring means maintain substantially the same ratioto each other; the said main spring exerted moment being equal to theload moment at one position of the load and varying therefromsubstantially in accordance with the change in the force of the mainspring means as the load is displaced from the said position; andauxiliary spring means interposed between said fixed element and saidrotatable element in such manner that the force of the auxiliary springmeans is wholly exerted on the pivot of the said rotatable element whenthe load is at the said position and upon movement or the load from saidposition exerts a turning moment on the rotatable element whichcompensates for the variation in the turning moment exerted by the mainspring means, whereby the net turning moment exerted by both said springmeans remains substantially equal to the turning moment exerted by theload.

3. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a. fixed element: a leversystem rotatable on said fixed element and having connection with theload; main spring means connected to the fixed element and to the saidsystem; the said main spring means and the said load operating on thesaid system in such manner that as the system is rotated by displacementof the load the proportional relation betwen the moment arm of theweight of the load and the moment arm of the force of said main springmeans remains substantially constant, and the moment exerted by the mainspring means on said system is in balance with the load moment at oneposition of said system and varies substantially in accordance with thechange in the main spring force as the load is displaced; and auxiliaryspring means connected to said fixed element and to the said system forexerting a turning moment thereon to compensate for the said variationbetween the load moment and the moment exerted by the main spring means;the force of said auxiliary spring means passing through the pivot ofsaid system when the said load and main spring moments are in balance.

4. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a fixed element; a leverrotatable on said fixed element and having connection with the load;main spring means connected on the said lever in such manner that as thelever is rotated by displacement of the load the turning moment exertedon the lever by the main spring means increases or decreases as theforce of the main spring means increases or decreases, respectively; andauxiliary spring means connected to said fixed element and to the leverfor exerting a turning moment thereon to compensate for the variation inthe turning moment exerted by the main spring means; the force of saidauxiliary spring means acting alonga line on one side of the pivot ofsaid lever when the load moment exceeds the moment of the main springmeans and acting along a line on the opposite side of the pivot of saidlever when the load moment is less than the moment of the main springmeans.

5. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a fixed element; a leverrotatable on said fixed element and having an arm connected to the load;main spring means connected to the fixed element and to another arm ofsaid later; the load and said main spring means operating on the saidlever in such manner that as the lever is rotated by displacement of theload the relation between the moment arm of the weight of the load andthe moment arm of the force of said main spring means remainssubstantially constant and the moment exerted by the main spring meanson said lever varies substantially in accordance with the change in themain spring force as the load is displaced; and auxiliary spring meansconnected to said fixed element and to an arm of the lever for exertinga turning moment thereon to compensate for the said variation betweenthe load moment and the moment exerted by the main spring means; themoments of the said load and of the said main spring means being inbalance when the line of force of the auxiliary spring means is inalignment with one arm of the lever.

6. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a frame; a lever pivoted onsaid frame with one arm thereof connected with the load; main springsprings connected with the frame and with the other arm of the lever;the said load and the said main spring means operating on the said leverin such manner as to tend to rotate it in opposite directions ofrotation; and auxiliary spring means connected with the frame and withthe arm of the lever which is connected with the load; the force of saidauxiliary spring means exerting a turning moment in the same directionof rotation as does the load when the load moment is less than themoment exerted by the main spring means, and exerting a turning momentin the same direction as does the main spring means when the load momentis greater than the moment exerted by the main spring means; the mainand auxiliary springs means together providing a net supporting effectsubstantially equal to the load throughout the displacement thereof.

7. A spring support for a load of known value subject to displacementwithin a predetermined range comprising a frame having depending sidemembers; an axle journaled in said side members near one end thereof; a.lever rotatable on said axle having an arm thereof connected to theload; main spring means connected to the frame near the opposite endthereof and to another arm of said lever; the load and the main springmeans operating on the lever in such manner that as the lever is rotatedby displacement of the load the turning moments exerted by the load andmain spring means are in oppositedirections of rotation and the momentarms of the load and of the main spring means maintain substantially thesame proportional relation to one another; and auxiliary spring meansconnected to the frame near said opposite end thereof and to the leverfor exerting a turning moment thereon to compensate for the variation inthe turning moment exerted by the main spring means; the force of saidauxiliary spring means acting along a line' on one side of the said axlewhen the :moment exerted by the main spring means exceeds the loadmoment and acting along a line on the other side of the said axle whenthe load moment exceeds the moment exerted by the main spring means.

8. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a frame; a lever pivoted onsaid frame with one arm thereof connected with the load; main springmeans connected with the frame and with the other arm of the lever; thesaid load and said main spring means operating on said lever in suchmanner that they exert turning moments about the pivot of said lever inopposite directions of rotation; and auxiliary spring means connectedwith the frame and with the arm of the lever which is connected with theload; the said spring means together providing a net supporting efiectsubstantially equal to the load throughout the displacement thereof; thesaid lever arms being so disposed and arranged in such manner that whenthe line of force of the load is at right angles to the axis of thelever arm connected with the load, the line of force of the main springmeans is perpendicular to the axis of the lever arm connected with saidspring means.

9. A spring support for a load of known value subject to displacementwithin a, predetermined range, comprising a frame; a lever pivotallymounted on said frame with one arm thereof connected with the load sothat the weight of the load exerts a turning moment on said lever in onedirection; main spring means connected between said frame and the otherarm of said lever so that the force of said main spring means exerts aturning moment on said lever in the reverse direction; the load and mainspring means operating on the lever in such manner that when the load isat one position of the said range of displacement the moment exerted byits weight is equal to the moment exerted by the force of said mainspring means and when the load moves either way from said position themoment exerted by the force of the main spring means increases as thesaid force increases and decreases as the said force decreases; andauxilthat throughout the said range of displacement 11 the momentexerted by the weight of the load throughout its movement.

10. A spring support for a known load subject to displacement within alimited range, compris- I in: a frame; a lever pivoted on said frame andhaving one arm connected with the load and so disposed that when theload is at one position of said predetermined range the arm ishorizontal and perpendicular to the line of pull of the load; mainspring means connected to the frame and to another arm of said lever,the said other arm being so disposed that when the load is at the saidposition the said other arm is p pe dicular to the line of the forceexerted by said main spring means; and auxiliary spring means connectedto said frame and to one of the lever arms and being so disposed thatwhen the load is at the said position the line of; the force exerted bysaid auxiliary means passes through the pivot of the lever whereby theforce of said auxiliary means exerts no turning moment at the saidposition of the load.

11. A spring support for a load of known value subject to displacementwithin a predetermined range, comprising a fixed element; an elementpivoted on said fixed element and rotatable about said pivot; the loadbeing connected to said rotatable element and exerting a turning momentin one direction about said pivot; main spring means connected to saidfixed element and to said rotatable element and exerting a turningmoment on the latter element in the opposite direction about said pivot:the said main spring means and the said load operating on the saidrotatable element in such manner the moment arms of the said turningforces have substantially the same proportional relation and the momentexerted by the said main spring means increases or decreases as the mainspring force increases or decreases. respectively; and auxiliary springmeans interposed between said fixed element and said rotatable elementand effective upon movement of the load to exert a tuming moment on therotatable element which compensates for the variation in the turningmoment exerted by the said main spring means; the force of saidauxiliary spring means when acting along a line on one side of saidpivot exerts a turning moment on the rotatable element in the samedirection of rotation as does the force exerted by the main springmeans, and the force of said auxiliary spring means when acting along aline on the opposite side of said pivot exerts a turning moment on therotatable element opposite in direction of rotation to that of themoment exerted by the force of the main spring means.

ALBERT J. LOEPSINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,208,064 Wood July 16, 19402,256,784 Wood Sept. 23, 1941 2,391,467 Loepsinger Dec; 25, 1945 352,395,730 Farkas Feb. 16, 1946

